- Project: Field Campaign Eastern Alps (Austria and Italy) | COOLER Project
- Project date: 05 August, 2022 – 11 August, 2022
- Team members: Isabel Wapenhans, Maxime Bernard and Lingxiao Gong
Overview  During the Summer of 2022, COOLER’s Isabel, Maxime, and University of Potsdam PhD colleague Lingxiao Gong visited the partially glaciated valleys of northern Italy and South-West Austria in the Eastern Alps to collect the first field samples for Isabel’s PhD project.
There, the role of past glaciations in developing topographic relief has not been addressed yet despite a clear imprint of past glaciers (see photos). How much have glaciers incised these valleys? And how fast? How is their erosive pattern influenced by the rocks’ vertical uplift due to tectonics? Answering these questions is crucial to evaluate the role of Quaternary glaciations in developing the present-day alpine topography, and to understand the interplay between climate and tectonics (see “Science behind the project”).
Previous studies based on physics and observations suggest, that the erosive power of a glacier is related to its sliding speed. The ice flux is enhanced around the equilibrium line altitude (ELA), i.e., the altitude where the accumulation of ice is matched by its melt loss. Therefore, glacial erosion is also enhanced at this altitude. This effect can be amplified by tectonic uplift rates that 1) keep providing topography above the ELA and the snowline, thus feeding glaciers with fresh ice, and 2) increase topographic slope steepness, which enhances the flow of glaciers and thus their erosive power. By comparing rock cooling, and thus, erosion histories with topographic patterns and the aforementioned erosion mechanisms we hope to gain a better understanding of how the Eastern Alps came to look the way they do today.
Furthermore, previous evidence shows a clear west-east trend in long-term exhumation rates in the Alps. To this end, we can compare the timing and pattern of glacial incision from the Eastern Alps to our Swiss samples in the western Alps (see “Field Campaign Switzerland”). By doing this, we wish to provide further insights into the role of tectonic uplift in controlling glacial erosion and glacial valley development.
4He/3He thermochronology on apatite is the most appropriate method to address the research questions mentioned above, as it allows us to more precisely date regional erosion trends linked with rock exhumation (see “Science behind the project”). It also provides better constraints at a local scale, such as the direction of the propagation of glacial erosion within a valley. Presently, Isabel is processing her samples in the lab, and hopes to share exciting discoveries soon!